CONTPJBUTIONS TO THE THEORY OF EVOLUTION 
455 
Frequency. 
2 
5 
18 
123 
798 
49 
1 
Total 996 
No. of lips 
1 
2 
3 
4 
5 
6 
7 
Mr. Mayer (p. 12) notes the failure of my curve of Type IV. I find for the 
constants : 
Mean = 4'8685 lips. 
/xj = *309,006, cr = *55588 
jUo = — *350,697 
fx^ = 1*181,718 
/3i = 4*16834 
= 12*37598 
/f, = 6*24694 
Ko = 1*06594 
Since Kg is so nearly unity we may use Type Y. 
Hence T find : 
p= 8*66184 y=- 8*811634 
(y must be negative since gg is negative) 
/x/ = 1*32270. 
Thus the curve starts at 6*19118 lips, or the one medusa with seven lips is 
theoretically excluded. Here I have worked with the uncorrected moments 
because the lij^s are discontinuous variants. Working with Sheppard’s corrective 
terms the limit is about six lips, and with the corrective terms suggested in my 
memoir on skew variation tlie limit is 7*65. Further we have .* 
log yo = 6*829,3633, 
distance from mean to mode = *30541, 
Sk. = *54941. 
The mode is thus at 5*17389, in good agreement with observation. 
The equation to the curve is, taking x iiositive from 6*19118 lips towards lesser 
values ; 
O.QQQ 84^5 
log y = 6*829,3633 — 8*66184 logo; — -y— 
